METHOD FOR PREPARATION OF ULTRATHIN DONOR CORNEAL TRANSPLANTS FOR POSTERIOR LAYERED KEROPLASTY BY SEQUENTIAL APPLICATION OF AUTOMATIC MICROKERATOME AND EXCIMER LASER Russian patent published in 2017 - IPC A61F9/00 

FIELD: medicine.

SUBSTANCE: invention is designed to form an ultrathin corneal disc (transplant) for posterior layered keratoplasty. At the first stage, the donor cornea, preserved in the Borzenka-Moroz medium, is mounted on an artificial front chamber. Ultrasound or OCT pachymetry (usually the thickness in the center of 750-900 microns) is performed. The first section is made with the Moria SLK 2 microkeratome with a longitudinal-type turbine with a caliper head of 450-500-550 mcm. Then ultrasound or OCT pachymetry is repeated. At the second stage, ablation with a flat beam using an excimer laser ophthalmic unit Microscan Visum (Optosystems, Troitsk) is performed to the depth necessary to obtain an ultrathin transplant (the residual thickness in the center of the transplant is 120-140 mcm). The excimer laser wavelength is 193 nm, repetition rate is 500 Hz, laser spot diameter is 0.9 mm, maximum ablation diameter is 9.0 mm, the ablation depth, as a rule, does not exceed 100 mcm (30-100 mcm). A piercer of the desired diameter (8-8.5 mm) is used to cut out the desired transplanto for ALK from the resulting blank. The obtained transplant thickness in the hydrated form in the central zone does not exceed 140 microns. After transplant dehydration in the eye of the recipient (usually not less than 30%), its thickness, respectively, does not exceed 100 microns.

EFFECT: predictable manufacture of a transplant with a given thickness without risk of perforation of the donor cornea and its rejection.

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